Chitosan-Functionalized Molten-Salt-Fabricated Carbon Foam With Zirconium Mof for Efficient Removal of Acid Red 18 Dye From Aqueous Solutions Publisher



Moteallemi A ; Dehghani MH ; Yaghmaian K ; Mahvi AH ; Nabizadeh Nodehi R ; Sanaei D
Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects Published:2025

Abstract

The uncontrolled release of synthetic dyes into aquatic environments poses serious environmental and public health risks, necessitating the development of efficient and sustainable adsorbents. This study presents a novel composite adsorbent synthesized by integrating two-dimensional UiO66 nanosheets with chitosan and N-doped porous carbon derived from waste polyethylene terephthalate (PET) via a molten salt approach. Characterization by XRD, FT-IR, FE-SEM, and nitrogen adsorption–desorption confirmed the successful fabrication of the composite. This 2D MOF–polymer–carbon hybrid exhibited a maximum adsorption capacity of 5000 mg g⁻¹ for Acid Red 18 (AR18), maintaining > 90 % removal efficiency over a pH range of 3–9. The adsorption process followed the pseudo-second-order kinetic model with a high correlation coefficient (R² > 0.999), and equilibrium data fitted the Langmuir isotherm closely, implying monolayer chemisorption. Thermodynamic analysis (ΔH° ≈ 45 kJ mol⁻¹) confirmed an endothermic and spontaneous process. The adsorbent retained ≥ 73 % of its initial capacity after eight regeneration cycles. Overall, this work demonstrates a scalable, eco-engineered strategy for transforming PET waste into a high-capacity, broad-spectrum dye adsorbent, marking a significant advance toward sustainable industrial wastewater treatment technologies. © 2025 Elsevier B.V., All rights reserved.